The present invention relates generally to apparatus for producing foundry molds and is more particularly directed to a system whereby foundry molds may be produced in mold halves by utilization of a single-station molding unit. Furthermore, the invention is directed toward a system which facilitates selective utilization of any one of a plurality of differently configured pattern devices simply by introducing such devices into the flow stream of the system. The system may be continuously operated by feeding empty mold boxes thereto, feeding pattern devices thereto and continuously transporting mold halves from the system.
In known apparatus of this type, pattern devices are generally moved on a conveyor track with molding boxes, particularly boxes adapted to form therein mold halves, being conveyed on a second track with the two tracks being arranged in a crossing configuration. A press head having an attached sand filling device may be moveable parallel to the conveyor track for the molding boxes which is directed to pass through a machine frame composed of the molding unit. Additionally, the molding unit is formed with lifting and lowering devices for bringing the pattern plates and molding boxes together during the mold forming operation
Depending on the type of mold halves which are to be. produced, pattern devices must be alternately moved into the molding unit from one of several waiting or standby positions. In the case of the aforementioned prior art system, the standby positions are separated from each other by the machine frame and the conveyor track for the molding boxes.
Known apparatus of this type has the disadvantage that operations which must be performed on the pattern devices while they are disposed in the standby position will require more than a single operator because of the spatial separation of the positions of the pattern devices. The operations referred to include cleaning and placing of chills, and it is desirable if such operations can be performed with greater efficiency and economy.
A more significant disadvantage of prior art devices resides in the fact that most of the partial operations which must be performed in producing a mold half must be performed within the molding unit. This fact has the result that respective partial operations must be performed successively, thereby resulting in relatively long station times and in comparatively low apparatus efficiencies.